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Updated: May 1, 2026
A Protocol for Rapid Post-mortem Cell Culture of Diffuse Intrinsic Pontine Glioma DIPG
Published on: March 7, 2017
Genomic analysis of diffuse intrinsic pontine gliomas identifies three molecular subgroups and recurrent activating
Pawel Buczkowicz1, Christine Hoeman2, Patricia Rakopoulos3
11] Division of Pathology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. [2] Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada. [3] Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. [4].
Abstract:
Diffuse intrinsic pontine glioma (DIPG) is a fatal brain cancer that arises in the brainstem of children, with no effective treatment and near 100% fatality. The failure of most therapies can be attributed to the delicate location of these tumors and to the selection of therapies on the basis of assumptions that DIPGs are molecularly similar to adult disease. Recent studies have unraveled the unique genetic makeup of this brain cancer, with nearly 80% found to harbor a p.Lys27Met histone H3.3 or p.Lys27Met histone H3.1 alteration. However, DIPGs are still thought of as one disease, with limited understanding of the genetic drivers of these tumors. To understand what drives DIPGs, we integrated whole-genome sequencing with methylation, expression and copy number profiling, discovering that DIPGs comprise three molecularly distinct subgroups (H3-K27M, silent and MYCN) and uncovering a new recurrent activating mutation affecting the activin receptor gene ACVR1 in 20% of DIPGs. Mutations in ACVR1 were constitutively activating, leading to SMAD phosphorylation and increased expression of the downstream activin signaling targets ID1 and ID2. Our results highlight distinct molecular subgroups and novel therapeutic targets for this incurable pediatric cancer.
Insights
Diffuse intrinsic pontine glioma (DIPG), a deadly pediatric brainstem cancer, comprises three distinct molecular subgroups. Researchers identified a novel ACVR1 gene mutation, revealing new therapeutic targets for this aggressive disease.
Area of Science:
- Pediatric oncology
- Neuro-oncology
- Cancer genomics
Background:
- Diffuse intrinsic pontine glioma (DIPG) is a highly fatal pediatric brainstem cancer with limited treatment options.
- Existing therapies often fail due to DIPG's location and the assumption of molecular similarity to adult brain tumors.
- Recent research indicates DIPG harbors unique genetic alterations, notably histone H3 mutations in approximately 80% of cases.
Purpose of the Study:
- To elucidate the molecular drivers of DIPG by integrating multi-omics data.
- To identify distinct molecular subgroups within DIPG.
- To uncover novel therapeutic targets for DIPG.
Main Methods:
- Integrated whole-genome sequencing with methylation, expression, and copy number profiling.
- Analyzed genetic alterations and their functional consequences in DIPG tumors.
Main Results:
- Discovered three distinct molecular subgroups of DIPG: H3-K27M, silent, and MYCN.
- Identified a recurrent activating mutation in the ACVR1 gene in 20% of DIPGs.
- Demonstrated that ACVR1 mutations lead to constitutive activation of the activin signaling pathway, increasing ID1 and ID2 expression.
Conclusions:
- DIPG is not a single disease but comprises distinct molecular subtypes.
- The ACVR1 gene mutation represents a novel, targetable driver in a subset of DIPGs.
- These findings provide critical insights into DIPG pathogenesis and open avenues for developing targeted therapies for this incurable pediatric cancer.
